This adds a configuration file for generating changelogs using the
GitLab API (done using Release Tools), as well as change Danger to
remind developers of these upcoming changes (similar to what we're doing
in gitlab-org/gitlab).
Omnibus, Pages and Helm are already using this new approach. Our current
plan is to also roll this out to remaining projects (GitLab Rails and
Gitaly) per May 22nd.
See https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/1564 for
more information.
